A related art peer-to-peer type communication system is configured to include a plurality of node apparatuses. The content data of various content are distributed and stored in a plurality of node apparatuses as replicated data (hereinafter, referred to as “replica”) of a plurality of content data. The content data is content data of film, music, and the like. Generally, one of the related art peer-to-peer type communication system is a distributed storage system which allows replicas to be used between node apparatuses. According to the related art, failure resistance and distribution efficiency of access are improved. The locations of replicas which are distributed and stored as described above are efficiently searched using a distributed hash table.
In addition, when acquiring the desired content, the node apparatus transmits to other node apparatuses a message for searching for the location of a replica of corresponding content data. According to this, the message is transmitted to a node apparatus, which manages the location of the replica of the corresponding content data, according to the DHT. Then, the node apparatus which transmitted the message acquires the information indicating the location of the replica from the node apparatus which manages the location. Accordingly, the node apparatus which transmitted the message can access a node apparatus which stores the replica of the content data corresponding to the search. Then, the node apparatus which transmitted the message can acquire (download) the replica.